美妙(měi miào) - wonderful, lovely, splendid in Mandarin

美妙 (měi miào) describes beauty you experience rather than beauty you look at: music, a voice, a feeling, an evening. The 妙 half adds a sense of something delicate and slightly beyond words.

Because of that it does not sit well on physical objects or on people. A woman is 美丽, a view is 美, a piece of music is 美妙. Saying 她很美妙 is not wrong so much as strange, like calling a person exquisite in English.

It is a written and slightly lyrical word. In everyday conversation people say 太好了 or 真棒. Keep 美妙 for the sentence where you actually want the reader to slow down.